1. Phase-detection autofocus (even using still targets and center-point only) wasn’t nearly as accurate as contrast detection.
2. The contrast-detection autofocus was about as accurate as the most careful manual focusing.
3. A few newer lenses did focus as accurately as contrast detection on 5D Mark III cameras but not on 5D Mark II cameras.
4. the newest Canon lenses (40mm f/2.8, 24mm f/2.8 IS, 28mm f/2.8 IS, 70-300mm L IS and 300mm f/2.8 IS II) focus more accurately when mounted to 5D Mark III camera but not on 5D Mark II cameras.

Here is an excerpt from this the latest Autofocus Reality Part 3B:
"Since we knew that the newest lenses autofocused accurately on 5DIII but not on 5DII cameras, the next step was obviously to compare an accurate AF lens on different camera bodies to see with which ones it was capable of accuracy."